//
// detail/reactive_socket_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_HPP
#define ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"

#if !defined(ASIO_HAS_IOCP) \
 && !defined(ASIO_HAS_IO_URING_AS_DEFAULT)

#include "asio/buffer.hpp"
#include "asio/error.hpp"
#include "asio/execution_context.hpp"
#include "asio/socket_base.hpp"
#include "asio/detail/buffer_sequence_adapter.hpp"
#include "asio/detail/memory.hpp"
#include "asio/detail/noncopyable.hpp"
#include "asio/detail/reactive_null_buffers_op.hpp"
#include "asio/detail/reactive_socket_accept_op.hpp"
#include "asio/detail/reactive_socket_connect_op.hpp"
#include "asio/detail/reactive_socket_recvfrom_op.hpp"
#include "asio/detail/reactive_socket_sendto_op.hpp"
#include "asio/detail/reactive_socket_service_base.hpp"
#include "asio/detail/reactor.hpp"
#include "asio/detail/reactor_op.hpp"
#include "asio/detail/socket_holder.hpp"
#include "asio/detail/socket_ops.hpp"
#include "asio/detail/socket_types.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace detail {

        template<typename Protocol>
        class reactive_socket_service :
                public execution_context_service_base<reactive_socket_service<Protocol> >,
                public reactive_socket_service_base {
        public:
            // The protocol type.
            typedef Protocol protocol_type;

            // The endpoint type.
            typedef typename Protocol::endpoint endpoint_type;

            // The native type of a socket.
            typedef socket_type native_handle_type;

            // The implementation type of the socket.
            struct implementation_type :
                    reactive_socket_service_base::base_implementation_type {
                // Default constructor.
                implementation_type()
                        : protocol_(endpoint_type().protocol()) {
                }

                // The protocol associated with the socket.
                protocol_type protocol_;
            };

            // Constructor.
            reactive_socket_service(execution_context &context)
                    : execution_context_service_base<
                    reactive_socket_service<Protocol> >(context),
                      reactive_socket_service_base(context) {
            }

            // Destroy all user-defined handler objects owned by the service.
            void shutdown() {
                this->base_shutdown();
            }

            // Move-construct a new socket implementation.
            void move_construct(implementation_type &impl,
                                implementation_type &other_impl)

            ASIO_NOEXCEPT
            {
                this->base_move_construct(impl, other_impl);

                impl.protocol_ = other_impl.protocol_;
                other_impl.protocol_ = endpoint_type().protocol();
            }

            // Move-assign from another socket implementation.
            void move_assign(implementation_type &impl,
                             reactive_socket_service_base &other_service,
                             implementation_type &other_impl) {
                this->base_move_assign(impl, other_service, other_impl);

                impl.protocol_ = other_impl.protocol_;
                other_impl.protocol_ = endpoint_type().protocol();
            }

            // Move-construct a new socket implementation from another protocol type.
            template<typename Protocol1>
            void converting_move_construct(implementation_type &impl,
                                           reactive_socket_service<Protocol1> &,
                                           typename reactive_socket_service<
                                                   Protocol1>::implementation_type &other_impl) {
                this->base_move_construct(impl, other_impl);

                impl.protocol_ = protocol_type(other_impl.protocol_);
                other_impl.protocol_ = typename Protocol1::endpoint().protocol();
            }

            // Open a new socket implementation.
            asio::error_code open(implementation_type &impl,
                                  const protocol_type &protocol, asio::error_code &ec) {
                if (!do_open(impl, protocol.family(),
                             protocol.type(), protocol.protocol(), ec))
                    impl.protocol_ = protocol;
                return ec;
            }

            // Assign a native socket to a socket implementation.
            asio::error_code assign(implementation_type &impl,
                                    const protocol_type &protocol, const native_handle_type &native_socket,
                                    asio::error_code &ec) {
                if (!do_assign(impl, protocol.type(), native_socket, ec))
                    impl.protocol_ = protocol;
                return ec;
            }

            // Get the native socket representation.
            native_handle_type native_handle(implementation_type &impl) {
                return impl.socket_;
            }

            // Bind the socket to the specified local endpoint.
            asio::error_code bind(implementation_type &impl,
                                  const endpoint_type &endpoint, asio::error_code &ec) {
                socket_ops::bind(impl.socket_, endpoint.data(), endpoint.size(), ec);
                return ec;
            }

            // Set a socket option.
            template<typename Option>
            asio::error_code set_option(implementation_type &impl,
                                        const Option &option, asio::error_code &ec) {
                socket_ops::setsockopt(impl.socket_, impl.state_,
                                       option.level(impl.protocol_), option.name(impl.protocol_),
                                       option.data(impl.protocol_), option.size(impl.protocol_), ec);
                return ec;
            }

            // Set a socket option.
            template<typename Option>
            asio::error_code get_option(const implementation_type &impl,
                                        Option &option, asio::error_code &ec) const {
                std::size_t size = option.size(impl.protocol_);
                socket_ops::getsockopt(impl.socket_, impl.state_,
                                       option.level(impl.protocol_), option.name(impl.protocol_),
                                       option.data(impl.protocol_), &size, ec);
                if (!ec)
                    option.resize(impl.protocol_, size);
                return ec;
            }

            // Get the local endpoint.
            endpoint_type local_endpoint(const implementation_type &impl,
                                         asio::error_code &ec) const {
                endpoint_type endpoint;
                std::size_t addr_len = endpoint.capacity();
                if (socket_ops::getsockname(impl.socket_, endpoint.data(), &addr_len, ec))
                    return endpoint_type();
                endpoint.resize(addr_len);
                return endpoint;
            }

            // Get the remote endpoint.
            endpoint_type remote_endpoint(const implementation_type &impl,
                                          asio::error_code &ec) const {
                endpoint_type endpoint;
                std::size_t addr_len = endpoint.capacity();
                if (socket_ops::getpeername(impl.socket_,
                                            endpoint.data(), &addr_len, false, ec))
                    return endpoint_type();
                endpoint.resize(addr_len);
                return endpoint;
            }

            // Disable sends or receives on the socket.
            asio::error_code shutdown(base_implementation_type &impl,
                                      socket_base::shutdown_type what, asio::error_code &ec) {
                socket_ops::shutdown(impl.socket_, what, ec);
                return ec;
            }

            // Send a datagram to the specified endpoint. Returns the number of bytes
            // sent.
            template<typename ConstBufferSequence>
            size_t send_to(implementation_type &impl, const ConstBufferSequence &buffers,
                           const endpoint_type &destination, socket_base::message_flags flags,
                           asio::error_code &ec) {
                typedef buffer_sequence_adapter <asio::const_buffer,
                ConstBufferSequence> bufs_type;

                if (bufs_type::is_single_buffer) {
                    return socket_ops::sync_sendto1(impl.socket_, impl.state_,
                                                    bufs_type::first(buffers).data(),
                                                    bufs_type::first(buffers).size(), flags,
                                                    destination.data(), destination.size(), ec);
                } else {
                    bufs_type bufs(buffers);
                    return socket_ops::sync_sendto(impl.socket_, impl.state_,
                                                   bufs.buffers(), bufs.count(), flags,
                                                   destination.data(), destination.size(), ec);
                }
            }

            // Wait until data can be sent without blocking.
            size_t send_to(implementation_type &impl, const null_buffers &,
                           const endpoint_type &, socket_base::message_flags,
                           asio::error_code &ec) {
                // Wait for socket to become ready.
                socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);

                return 0;
            }

            // Start an asynchronous send. The data being sent must be valid for the
            // lifetime of the asynchronous operation.
            template<typename ConstBufferSequence, typename Handler, typename IoExecutor>
            void async_send_to(implementation_type &impl,
                               const ConstBufferSequence &buffers,
                               const endpoint_type &destination, socket_base::message_flags flags,
                               Handler &handler, const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_socket_sendto_op <ConstBufferSequence,
                endpoint_type, Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(success_ec_, impl.socket_,
                                  buffers, destination, flags, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::write_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_send_to"));

                start_op(impl, reactor::write_op, p.p, is_continuation, true, false);
                p.v = p.p = 0;
            }

            // Start an asynchronous wait until data can be sent without blocking.
            template<typename Handler, typename IoExecutor>
            void async_send_to(implementation_type &impl, const null_buffers &,
                               const endpoint_type &, socket_base::message_flags,
                               Handler &handler, const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_null_buffers_op <Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(success_ec_, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::write_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_send_to(null_buffers)"));

                start_op(impl, reactor::write_op, p.p, is_continuation, false, false);
                p.v = p.p = 0;
            }

            // Receive a datagram with the endpoint of the sender. Returns the number of
            // bytes received.
            template<typename MutableBufferSequence>
            size_t receive_from(implementation_type &impl,
                                const MutableBufferSequence &buffers,
                                endpoint_type &sender_endpoint, socket_base::message_flags flags,
                                asio::error_code &ec) {
                typedef buffer_sequence_adapter <asio::mutable_buffer,
                MutableBufferSequence> bufs_type;

                std::size_t addr_len = sender_endpoint.capacity();
                std::size_t bytes_recvd;
                if (bufs_type::is_single_buffer) {
                    bytes_recvd = socket_ops::sync_recvfrom1(impl.socket_,
                                                             impl.state_, bufs_type::first(buffers).data(),
                                                             bufs_type::first(buffers).size(), flags,
                                                             sender_endpoint.data(), &addr_len, ec);
                } else {
                    bufs_type bufs(buffers);
                    bytes_recvd = socket_ops::sync_recvfrom(
                            impl.socket_, impl.state_, bufs.buffers(), bufs.count(),
                            flags, sender_endpoint.data(), &addr_len, ec);
                }

                if (!ec)
                    sender_endpoint.resize(addr_len);

                return bytes_recvd;
            }

            // Wait until data can be received without blocking.
            size_t receive_from(implementation_type &impl, const null_buffers &,
                                endpoint_type &sender_endpoint, socket_base::message_flags,
                                asio::error_code &ec) {
                // Wait for socket to become ready.
                socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);

                // Reset endpoint since it can be given no sensible value at this time.
                sender_endpoint = endpoint_type();

                return 0;
            }

            // Start an asynchronous receive. The buffer for the data being received and
            // the sender_endpoint object must both be valid for the lifetime of the
            // asynchronous operation.
            template<typename MutableBufferSequence,
                    typename Handler, typename IoExecutor>
            void async_receive_from(implementation_type &impl,
                                    const MutableBufferSequence &buffers, endpoint_type &sender_endpoint,
                                    socket_base::message_flags flags, Handler &handler,
                                    const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_socket_recvfrom_op <MutableBufferSequence,
                endpoint_type, Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                int protocol = impl.protocol_.type();
                p.p = new(p.v) op(success_ec_, impl.socket_, protocol,
                                  buffers, sender_endpoint, flags, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::read_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_receive_from"));

                start_op(impl,
                         (flags & socket_base::message_out_of_band)
                         ? reactor::except_op : reactor::read_op,
                         p.p, is_continuation, true, false);
                p.v = p.p = 0;
            }

            // Wait until data can be received without blocking.
            template<typename Handler, typename IoExecutor>
            void async_receive_from(implementation_type &impl, const null_buffers &,
                                    endpoint_type &sender_endpoint, socket_base::message_flags flags,
                                    Handler &handler, const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_null_buffers_op <Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(success_ec_, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::read_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_receive_from(null_buffers)"));

                // Reset endpoint since it can be given no sensible value at this time.
                sender_endpoint = endpoint_type();

                start_op(impl,
                         (flags & socket_base::message_out_of_band)
                         ? reactor::except_op : reactor::read_op,
                         p.p, is_continuation, false, false);
                p.v = p.p = 0;
            }

            // Accept a new connection.
            template<typename Socket>
            asio::error_code accept(implementation_type &impl,
                                    Socket &peer, endpoint_type *peer_endpoint, asio::error_code &ec) {
                // We cannot accept a socket that is already open.
                if (peer.is_open()) {
                    ec = asio::error::already_open;
                    return ec;
                }

                std::size_t addr_len = peer_endpoint ? peer_endpoint->capacity() : 0;
                socket_holder new_socket(socket_ops::sync_accept(impl.socket_,
                                                                 impl.state_, peer_endpoint ? peer_endpoint->data() : 0,
                                                                 peer_endpoint ? &addr_len : 0, ec));

                // On success, assign new connection to peer socket object.
                if (new_socket.get() != invalid_socket) {
                    if (peer_endpoint)
                        peer_endpoint->resize(addr_len);
                    peer.assign(impl.protocol_, new_socket.get(), ec);
                    if (!ec)
                        new_socket.release();
                }

                return ec;
            }

            // Start an asynchronous accept. The peer and peer_endpoint objects must be
            // valid until the accept's handler is invoked.
            template<typename Socket, typename Handler, typename IoExecutor>
            void async_accept(implementation_type &impl, Socket &peer,
                              endpoint_type *peer_endpoint, Handler &handler, const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_socket_accept_op <Socket, Protocol, Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(success_ec_, impl.socket_, impl.state_,
                                  peer, impl.protocol_, peer_endpoint, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected() && !peer.is_open()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::read_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_accept"));

                start_accept_op(impl, p.p, is_continuation, peer.is_open());
                p.v = p.p = 0;
            }

#if defined(ASIO_HAS_MOVE)
            // Start an asynchronous accept. The peer_endpoint object must be valid until
            // the accept's handler is invoked.
            template <typename PeerIoExecutor, typename Handler, typename IoExecutor>
            void async_move_accept(implementation_type& impl,
                const PeerIoExecutor& peer_io_ex, endpoint_type* peer_endpoint,
                Handler& handler, const IoExecutor& io_ex)
            {
              bool is_continuation =
                asio_handler_cont_helpers::is_continuation(handler);

              typename associated_cancellation_slot<Handler>::type slot
                = asio::get_associated_cancellation_slot(handler);

              // Allocate and construct an operation to wrap the handler.
              typedef reactive_socket_move_accept_op<Protocol,
                  PeerIoExecutor, Handler, IoExecutor> op;
              typename op::ptr p = { asio::detail::addressof(handler),
                op::ptr::allocate(handler), 0 };
              p.p = new (p.v) op(success_ec_, peer_io_ex, impl.socket_,
                  impl.state_, impl.protocol_, peer_endpoint, handler, io_ex);

              // Optionally register for per-operation cancellation.
              if (slot.is_connected())
              {
                p.p->cancellation_key_ =
                  &slot.template emplace<reactor_op_cancellation>(
                      &reactor_, &impl.reactor_data_, impl.socket_, reactor::read_op);
              }

              ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                    &impl, impl.socket_, "async_accept"));

              start_accept_op(impl, p.p, is_continuation, false);
              p.v = p.p = 0;
            }
#endif // defined(ASIO_HAS_MOVE)

            // Connect the socket to the specified endpoint.
            asio::error_code connect(implementation_type &impl,
                                     const endpoint_type &peer_endpoint, asio::error_code &ec) {
                socket_ops::sync_connect(impl.socket_,
                                         peer_endpoint.data(), peer_endpoint.size(), ec);
                return ec;
            }

            // Start an asynchronous connect.
            template<typename Handler, typename IoExecutor>
            void async_connect(implementation_type &impl,
                               const endpoint_type &peer_endpoint,
                               Handler &handler, const IoExecutor &io_ex) {
                bool is_continuation =
                        asio_handler_cont_helpers::is_continuation(handler);

                typename associated_cancellation_slot<Handler>::type slot
                        = asio::get_associated_cancellation_slot(handler);

                // Allocate and construct an operation to wrap the handler.
                typedef reactive_socket_connect_op <Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(success_ec_, impl.socket_, handler, io_ex);

                // Optionally register for per-operation cancellation.
                if (slot.is_connected()) {
                    p.p->cancellation_key_ =
                            &slot.template emplace<reactor_op_cancellation>(
                                    &reactor_, &impl.reactor_data_, impl.socket_, reactor::connect_op);
                }

                ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
                        &impl, impl.socket_, "async_connect"));

                start_connect_op(impl, p.p, is_continuation,
                                 peer_endpoint.data(), peer_endpoint.size());
                p.v = p.p = 0;
            }
        };

    } // namespace detail
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // !defined(ASIO_HAS_IOCP)
//   && !defined(ASIO_HAS_IO_URING_AS_DEFAULT)

#endif // ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_HPP
